Microfluidics is a young scientific discipline that now it is ready to be incorporated in routine process by the companies. The wide range of application includes biochemistry, cellomics and most recently particle synthesis. Microfluidics used as microdroplet generator has been widely exploited to fabricate particles with different size, different composition, texture and aspect ratio. The basic idea of the book is to provide a handbook provided by the protocols to be used and consulted in case of microgel fabrication. After the chapter of introduction where the economical scenario is prospected, the next chapters display and report either the design, either the protocol of fabrication of the microfluidic device. Characterization of the microfluidic particles is also provided. The book grew out in a experimental environment and to date, it provide solutions for practical problem rescontred in day by day experiments. At the same time the book includes a theoretical approach of the mass balance and of the reaction in order to define the geometrical size to complete the reaction.